Details

An updated thunderbird package that fixes two security issues is nowavailable for Red Hat Enterprise Linux 4 and 5.

The Red Hat Security Response Team has rated this update as having criticalsecurity impact. Common Vulnerability Scoring System (CVSS) base scores,which give detailed severity ratings, are available for each vulnerabilityfrom the CVE links in the References section.

Mozilla Thunderbird is a standalone mail and newsgroup client.

A flaw was found in the processing of malformed content. An HTML mailmessage containing malicious content could cause Thunderbird to crash or,potentially, execute arbitrary code with the privileges of the user runningThunderbird. (CVE-2012-0442)

The same-origin policy in Thunderbird treated http://example.com andhttp://[example.com] as interchangeable. A malicious script could possiblyuse this flaw to gain access to sensitive information (such as a client'sIP and user e-mail address, or httpOnly cookies) that may be included inHTTP proxy error replies, generated in response to invalid URLs usingsquare brackets. (CVE-2011-3670)

Note: The CVE-2011-3670 issue cannot be exploited by a specially-craftedHTML mail message as JavaScript is disabled by default for mail messages.It could be exploited another way in Thunderbird, for example, when viewingthe full remote content of an RSS feed.

All Thunderbird users should upgrade to this updated package, whichresolves these issues. All running instances of Thunderbird must berestarted for the update to take effect.

Solution

Before applying this update, make sure all previously-released erratarelevant to your system have been applied.